import _ from 'lodash';
import jsonpack from 'jsonpack';
import merge from 'deepmerge';
import basex from 'base-x';


class JBase62 {
    static #instance = null

    static getInstance = (characters = null) => {
        if (characters || !JBase62.#instance) {
            JBase62.#instance = new JBase62(characters)
        }
        return JBase62.#instance
    }

    #basex = null

    constructor(characters = "") {
        if (!characters && !JBase62.#instance) {
            throw new "characters is required"
        }

        if (characters) {
            this.#basex = basex(characters)
        } else if (JBase62.#instance) {
            return JBase62.#instance
        }
    }

    encode = (json = {}) => {
        const jsonString = JSON.stringify(json, (__, v) => v === undefined ? null : v)
        const binaryString = jsonpack.pack(jsonString)
        return this.#basex.encode(Buffer.from(binaryString))
    }

    decode = (base62 = '', defaultValue = {}) => {
        if (base62 === undefined || base62 === '') {
            return defaultValue
        }

        try {
            const binaryString = this.#basex.decode(base62).reduce((carry, bin) => carry + String.fromCharCode(bin), "")
            const jsonString = jsonpack.unpack(binaryString)
            return typeof (jsonString) === 'string' ? JSON.parse(jsonString) : jsonString
        } catch (e) {
            console.warn('JBase62.decode', e)
            return defaultValue
        }
    }

    get = (base62, path, defaultValue) => _.get(this.decode(base62), path, defaultValue)

    set = (base62, path, value) => {
        const obj = this.decode(base62)
        _.set(obj, path, value)
        return this.encode(obj)
    }

    assign = (base62, data = {}, isDeepMerge = false) => this.encode(isDeepMerge ? merge(this.decode(base62), data) : Object.assign(this.decode(base62), data))
}

export default JBase62